Alex McColgan

If one new discovery calls old models into question, it's worth throwing the old playbook out, no matter the mountain of work it creates, if it means getting closer to understanding the true nature of our universe.

Why does reality have a speed limit?

It is common knowledge that the speed of light is the fastest that anyone can go, but why does this cap on causality exist?

And why is it exactly 299,792,458 metres per second?

Why not more?

Why not less?

If you're like me, you've wondered about these strange properties of light, but recently I think I might have found an answer, and it lies in hyperbolic geometry.

And the more I've considered it, the more it's blown my mind.

I'm Alex McColgan and you're watching Astrum.

Join with me today for the third part in our series on the unseen world and bring together what we have learned so far to try to answer some of the biggest questions about why our universe is the way it is.

Before we begin, I should mention that this is a continuation of a model that has been developed in collaboration between me and my brother, which we began in this video about 4D space, and continued exploring in this video about the shape of our universe.

If you haven't watched those videos yet, I would highly recommend you check them out, as we will be blending both concepts together in this video.

Check the links in the description or the top right if you need a refresher.

With that out of the way, let's talk a little bit about light.

There is an interesting observation we can make about light.

From an external perspective, it appears as if light is travelling at 299,792,458 metres per second.

This is true no matter what perspective you look at it from, whether you are at standstill, whether you are moving towards it or away from it.

It always looks as if it is travelling at this speed.

However, there is a single, interesting exception to this rule which had always puzzled me.

The photon's perspective.